Hey guys, me (guitarist), my bassist (plus vocals) and my drummer want to start recording some material soon.
At the moment all we're using to get ideas is recording on my crappy mp3 player.

We have about 3-4 high quality mics (according to my bassist, his mum's a singer and has really good mics or something) and my sister is giving us 2 singstar mics + the audio interface that the game comes with (2 mic inputs -> interface -> usb).

Speaking of which, if our good mics have that 1/4 inch, instrument sized jack, what kind of converter will i need? The singstar interface is 3.5mm, but do i buy a 1/4 inch mono to 3.5mm stereo, or the other way around or what? What's the technical specs of the singstar hardware anyway? i haven't been able to find anything on google.

We're quite content with recording one instrument at a time and putting it together on audacity or kristal. Recording the guitar, bass and vocals seems easy enough...we figure we'd just use the singstar interface (hey it's not great, but it'll do), but how do we go about recording drums? We want to use 4 mics for it (1 on the bass drum, 1 for the snare and two overheads).

I was thinking we'd mix the drums through a 5 channel mixer and feed that to the interface, but most 5 channel mixers only have 1 channel with a mic preamp...i'm actually a bit out of the mix with this choice...any recommendations?
Duuuuuuude, drums will never sound good that way but I must commend you on going to extreme lengths to getting the job done.

My easiest and best recommendation would be to purchase a Firepod ($300). That gives you 8 preamps via firewire and is by far the best bang for the buck.

If you only have 4 mics to do drums, I would suggest using the Glyn Johns Drum Miking Technique (google!).

If you are on a seriously hardcore budget than all I can suggest is experiment the hell out of what you have! To answer the question relating to 3.5mm adapters: you can pickup a 1/4" to 3.5mm adapter and that will work with your singstar interface.
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haha yeah we are on a bit of a budget. We would really like to just record with what we have right now, even if it is shitty quality. We just want some basic recordings to get our stuff out there, then later on down the track we'll book into a studio or buy better gear. That being said, i'm seeing how i can make the best out of our situation. (i'm trying to look for a setup where we can use our nice mics). I probably can only push the budget to $200AU tops for the moment (anything more will require more time).

I read up a bit about the 5 channel mixer...so with something like this:
Would only be able to record 1 track directly from a mic, with the other 4 tracks requiring a mic pre-amp of some sort? I could go for a 10 channel mixer with 4 preamp channels for $200, that might come in handy down the track.

That presonus firepod looks nice, but it costs about $1000AU from local stores (sydney based).

Thanks for the tips though.